Well I don't see how 4 rounds is possible, but it won't be over this round round for sure. I also think it is a terrible idea that any team is out with over 30 cards. Also, keeping cards hidden is a great skill that would be removed with that idea.
What do you mean by that? It would let you keep 30 cards hidden!
If you meant keeping the steamers hidden was a great skill, then nah, it was predicted that you have them.
4 rounds:
1. aether plays and loses vs the other teams
2. team A wins one (A - ~65 B ~ 35)
3. team B wins one (A - ~35 B ~ 35)
4. one of them wins finally.
Or
1. aether loses one, beats one (40/35/65)
2. team 65 gets a bye
3. aether and loser play one, one of them wins
4. team 65 wins
Or
1. aether beats both -> (35/35/70)
2. aether loses one -> (35/40/40)
3. one of the teams gets a bye
4. final match
In fact, 4 rounds are very likely due to having 2 teams in the sweet spot, and 2 rounds to kill them.